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What's a heat shield for?

What does the heat shield do

There’s some info about their function written into this page:

That’s only one resource I found from a search; looks like there’s lots more.

I really think you should have left the reply post that was on this thread. After all this forum does also provide entertainment for people.


This probably deserves its own topic as far as the situation we’re in with the moderation and the Ask Someone posts, and I don’t want to get into this in this thread. But in short, I am wondering what the entertainment you’re referring to might be - for the posters or the person asking the question?

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The heat shield on my space capsule keeps me from cooking to death when I reënter the atmosphere.


The heat shield is a misunderstood part. We Subaru owners know it as the thing that rattles and never stops starting at mile 36,001. Kidding aside, my understanding of the “heat shield” is that it is intended to primarily do two things. First, it can help prevent fires when a person parks over grass or brush. It “shields” the heat from the hottest part of the exhaust system. Second, the catalyst in a catalytic converter likes to work hot. Really hot. When it’s not hot, it does not work properly and the temporary emissions are higher than we all want them to be (we being the general public). So the heat shield helps to retain the heat in the device a bit longer. Say when you stop to go into a store for a few minutes. It can also help the device to heat up quicker. I’m willing to be proven wrong on this by anyone, so feel free to challenge my comments.


When you set gasoline alight, as is done inside a car engine, it creates a lot of heat. If an exhaust heat shield falls off it can cause that part of the floor of the car to get really hot, even melt the carpet. There’s heat shields designed to protect sensitive electronic parts from getting too hot and malfunctioning also. There’s a heat shield covering my Corolla’s exhaust manifold, not sure if that’s there to prevent exhaust manifold heat from reaching the near-by radiator, or to prevent the owner from burning themselves while poking around under the hood.

The heat shield is to seperate the car, you and the carpet from the heat of the converter.


I think the words “heat” and “shield” give big clue as to their purpose.


It keeps me from burning my leg on my motorcycle muffler.

On my old 70’s dirt bike the only thing they did was slightly lessen the severity of the burn, if anything at all.


Well, you know, better a first degree burn than a second degree burn. Someone will ask “is that a tattoo on your leg?” and you say, “no it’s a brand”.
But if burning your leg on the exhaust is a repeated problem, maybe you should dress in appropriate motorcycle riding gear. I cringe every time I see someone riding in shorts and flip flops.


lol … Know it all too well. I had those horizontal lines on the inside of my right calf during my teenage motorcycle dirt-bike years. Common sense would say a person would wear some tough jeans rather than short pants, but common sense didn’t apply in those days :wink: And you are absolutely right, first degree is better than second!

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Well, under the entertainment aspect it brings to mid a certain Calif. state Representative. I’m sure he’d like to forget this one but hey, ya just can’t fix stupid. Back in the late 70’s / early 80’s (i’m older give me a brake) the newly minted State rep Matsui was tooling around Sacramento driving his nice new state leased Porsche 911 clone- the one with the swoopy back), looking for a place to park so he could interface with some of his co-conspirators ( fellow party members- let’s party). Well, at that time of the year there are a lot of dead leaves in the gutters waiting pickup. Ace here decided to just park it showing a lot of good judgement??? One guess what happened. Heat shield + dry leaves = completely toasted car. heat shield is less hot than what’s behind it but not by much. The shield acts as some protection from road debris just in case you run over a plastic milk bottle-

There’s nothing like running into a plastic bag with your nice shiny chrome motorcycle exhaust pipe. It melts onto the pipe and then turns black.
Most street bikes with chrome exhausts had double wall pipes, a pipe inside a pipe, which kind of prevented the chrome from turning blue from the heat. It would get hot enough to melt a plastic bag but not hot enough to burn it completely off.
Taking the plastic fairing off of my present motorcycle in order to service the engine made me realize that sport bike fairings actually make the bike less costly to manufacture. When the engine and frame is hidden by a fairing, the engine and frame doesn’t have to be polished and pretty, and the exhaust header can be single wall stainless steel.

heat shield? my taurus does not have them but my chevy does. both are v6 motors in sedan size vehicles